Displaying fish in an aquarium has been a popular hobby throughout the world for hundreds of years. The first glass aquariums were constructed in the 1800's. Since that time the basic design of the fish aquarium has changed little. Fish are to this day kept most frequently in a tank of water which has a relatively small viewing area in relation to the volume of water contained therein. Aquariums are almost always illuminated from above, which prevents viewing the fish from above, which is how fish are almost always observed in nature. Almost all fish tanks are the same generally cylindrical or rectangular shape. The modern fish tank is typically made of acrylic instead of glass, it may have a filtration system on top instead of on the side or bottom, but it remains simply a standing tank of water.
The natural habitat of most fish is not a standing body of water. Modern aquariums do an inadequate job mimicking the environment of stream and river-dwelling fish. It is difficult and expensive to mimic a coastal reef environment in any commercially available aquarium. Moreover, no low-cost, simple-to-operate and maintain, and energy efficient aquarium is available that replicates a coastal environment replete with waves and sandy shore.
The present invention accomplishes all of the above in a simple, inexpensive and elegant manner. It allows a fish hobbyist to add an additional, visually exciting aquarium at a minimal cost to an existing, traditional aquarium. Because of its low weight per length it can be easily suspended from most ceilings, providing a stunning and unique display. The aquarium length can range from a foot to more than one hundred feet, as desired. It is self-cleaning due to its directional current and the frequent, nearly complete, exchanges of water. Because there is such a high rate and percentage of water exchange, an unusually large number of fish per gallon of water can thrive in the aquarium of the present invention.
This invention is the outgrowth of experiments to construct a working, closed circuit tubular aquarium. By the fall of 2001 I had a functioning tubular aquarium, but I could not find simple solutions to several aspects of maintaining a healthy environment. For example, while I could easily introduce fish to the aquarium, I could not easily remove a fish without dismantling much of the prototype. Over time, air dissolved in the aquarium water escapes and forms increasingly larger air bubbles, especially in horizontal sections of tubing. These air bubbles interfere with water flow and are difficult to remove.
At approximately this time I did a patent search for tubular aquariums. I came across U.S. Pat. No. 5,605,115 issued to Dale on Feb. 25, 1997. When I examined the drawings and specifications, I saw that my tubular aquarium was a substantial improvement in simplicity and functionality, yet my design at the time was still too impractical for sale.
Later in the year I decided to rethink the concept of the tubular aquarium. I wanted to keep the aspects of it that were so appealing: fish swimming long distances, maximized viewing area, and the choice of mounting on a wall or hanging from a ceiling.
I deconstructed the tubular aquarium into its simplest components, namely, a length of tubing, water entering one end of the tube, and water draining from the other end of the tube. To get the water to drain from the tube, I angled the tube slightly upward. Doing so caused the inflowing water at the upper end to run down the tube in the manner of a stream or river. While I was experimenting with various drain options I discovered I could make use of the siphon effect in a novel way if I positioned the reservoir below the aquarium. While a periodic drain pump can mimic the effect of a drain siphon, a siphon is simple, foolproof and inexpensive. A siphon will not stress or harm beneficial microorganisms such as plankton the way a pump can. Using a siphon in different configurations allows the aquarium to replicate natural stream, river, reef and seashore environments. Another modification of the siphon creates a healthy environment for many times the usual limit of fish compared with a non-modified standard aquarium.
As the water in the aquarium rises, at a predetermined water level the siphon self-primes and empties the aquarium. The amount of water left in the aquarium is predetermined by the height of the siphon's open end inside the aquarium, or by an opening elsewhere in the siphon assembly, which breaks the siphon effect as soon as the water in the aquarium empties to that level and air enters. The water left in the aquarium is important to the well being of the fish. It remains a relatively quiet pool of water where the fish can rest when not swimming with or against the water inflow.
The rate at which water enters the upper end of the aquarium is easily controlled by adjustment of pump-size, flow-rate, inflow tubing diameter, and/or by partially compressing the inflow tubing to restrict water flow. The rate at which the siphon drains the aquarium is easily controlled by the configuration and size of the siphon's open end, the diameter of the siphon, the diameter of the drain tubing attached to the siphon, and/or by restricting the drain tubing to decrease water outflow.
The frequent, near total exchange of water in the aquarium eliminates almost all of the waste that would normally accumulate in the corners and along the bottom of traditional aquariums. As such, fish are minimally exposed to their own waste. There is no portion of the aquarium in which unhealthy microorganisms can reproduce in stagnant water. Cleaning needs to be performed much less frequently and takes relatively little time. The self-cleaning attribute of this invention was a serendipitous result of the redesign of the aquarium.
Cleaning aquariums is an unpleasant chore for most aquarium owners. Cleaning is necessary to ensure a healthy aquatic environment. Aquarium filters cannot remove all of the waste and debris, and thus periodic aquarium cleanings are required.
A number of inventions address this need for periodic aquarium cleaning. All of these inventions, including U.S. Pat. No. 4,913,811 issued to Huang, et al., U.S. Pat. No. 5,640,930 issued to Kirby, U.S. Pat. No. 5,690,054 issued to Allen, U.S. Pat. No. 5,290,437 issued to Lin and U.S. Pat. No. 460,809 issued to Gunther, as well as other prior art devices, require complex filtering systems or vacuuming units to clean the bottom to remove settled waste. U.S. Pat. No. 5,849,185 issued to Judy, and U.S. Patent Application No. 20040251186 submitted by Ohanian, detract from the natural beauty of an aquarium.
All, except U.S. Pat. No. 5,849,185 issued to Judy, are relatively expensive to manufacture. The Judy device needs to be cleaned periodically itself because it sits inside the fish tank and filth and algae accumulate along its walls. In addition, it substantially reduces the viewing area of the aquarium.
Because commercially sold aquariums do not provide for automatic and frequent exchange of large volumes of water, waste is left trapped in corners and close to the surface. None of the above referenced prior art removes waste and debris floating in the water unless it is already very near the bottom of the aquarium.
Referring again to U.S. Pat. No. 5,605,115 issued to Dale, such a device is far from an ideal environment for keeping fish. For example, there is no simple way to remove a fish if it is dead, diseased, or injured. Waste accumulates at the bottom of the horizontal sections of such a device, and there is no way provided for its removal except for the circulation of the water through the tubing. From testing, the rate of water flow required to flush away the waste is high enough to be detrimental to the health of most fish. One other problem not addressed in the Dale patent is the removal of air pockets in sections of the tubing. Over time air that is dissolved in the aquarium water escapes and forms increasingly large air bubbles, especially in horizontal sections of tubing. These air bubbles interfere with water flow and are difficult to remove. There is no solution offered to this problem in the Dale disclosure.
U.S. Pat. No. 5,647,983 is an aquarium system designed for the treatment of aquarium water. It is another example of a piecemeal solution to designing an integrated aquarium system. U.S. Pat. No. 5,647,983 does not address the less than natural environment inside the aquarium. The aquarium is a modification of a standard aquarium without providing an enhanced habitat. The modifications required also detract from the aesthetic qualities of even a standard aquarium. The preferred implementation of U.S. Pat. No. 5,647,983 is as a salt water aquarium but the need for water pumps to achieve wave and current flow inside the aquarium is not addressed. The plankton that are spared in the stand alone filter will be harmed once they flow into the aquarium and are sucked into one of the necessary pumps. In the instant invention there is only a single water pump that pumps water from the bottom of the reservoir into the aquarium. Plankton or other beneficial floating organisms remain safe in the reservoir, not needing to pass through the water pump.
The rotating filter wheel in U.S. Pat. No. 5,647,983 doubles as the mechanism to transfer water between the reservoir and the aquarium. This is an inefficient transfer mechanism that requires that the reservoir be placed close to and at nearly the same level as the aquarium. Such a system detracts from the aesthetic value of the aquarium, and even with the reservoir placed in close proximity to the aquarium it still is not be able to provide a high rate of water exchange.
In addition, in U.S. Pat. No. 5,647,983 Limcaco does not address the problem of how to increase the percentage of water in the aquarium that is filtered on a regular basis. There is nothing in such an aquarium system that minimizes stagnant areas of water within the aquarium. U.S. Pat. No. 5,647,983 is described as an aquarium system while it is in essence a filtering system requiring special connections and other modifications to a standard aquarium.
Prior art devices have addressed either improving the aquarium or the filtration of aquarium water. However, the prior art devices each generally improve upon only one or two small aspects of an aquarium system. Clearly, then, there is a need for an aquarium system that improves upon the prior art by providing:                1. Greater ratio of viewing area to water volume;        2. Enhanced viewing experience watching fish interact in a more natural environment;        3. The ability to view fish from the unusual perspectives of from the top down, from the bottom up, and from end to end;        4. Simplicity of design, requiring only one moving part: the impeller inside a single water pump;        5. An uncluttered aquarium design, as equipment such as filters and heaters are set up in the reservoir which can be hidden from view;        6. Lower operating costs, as only a single pump is required, and the filters in the reservoir are powered by downward water flow when the aquarium periodically drains by gravity;        7. Greatly increased number of fish that can be well-maintained therein compared to any other aquarium with the same volume of water;        8. Improved physical and mental health of fish due to emulation of a more natural aquatic environment;        9. A reservoir that acts as a giant buffer, maintaining a stable temperature and high water quality in the aquarium; and        10. With micro-chip controlled LED lighting at one or both ends of the tube-shaped aquariums, the aquariums become a decorative light sculpture with ever changing hues reflecting off the fish.        
The present invention accomplishes these objectives.